<abstract xmlns="http://www.w3.org/1999/xhtml"><p>Flocculants are chemicals that mediate flocculation process, by aggregating colloids from suspension to form floc. Chemical flocculants are hazardous to the environment, which inform the search for safer and eco-friendly alternatives from microorganisms. Bacterial strains were isolated from water and sediment samples collected from Sodwana Bay, South Africa, and physiological properties of the bacterial strains were observed. Flocculation test using kaolin clay suspension was done on all isolates and the ones that showed flocculating activity were identified molecularly using 16 rRNA gene sequence analysis. Forty marine bacteria isolates were gotten from sediments and water samples collected from Sodwana Bay. Most of the isolates exhibited a range of colony pigmentation (pink, creamy, yellow, and white). After purification of individual isolates, they were screened for their potential to produce bioflocculant. The result revealed that isolates marked SOD3, SOD10, SOD12, SOD26, SOD27, SOD28, SOD32, SOD33 and SOD34 produced bioflocculants as shown by the flocculating activities from their crude extract. All these isolates showed good flocculation of kaolin clay suspension above 60% (flocculating activity) except SOD12. These bioflocculant producing isolates were identified as <italic>Pseudoalteromonas sp</italic>, <italic>Alcaligenes faecalis</italic>, <italic>Bacillus subtilis</italic>, <italic>Bacillus cereus</italic>, <italic>Bacillus stratosphericus</italic>. The results showed Sodwana Bay, South Africa as a reservoir of bacteria with potential to produce flocculants. However, further studies on the optimisation of culture conditions for bioflocculant production, extraction, characterisation and application of isolates is on the way to underscore the biotechnological importance of these microbes as producers of substitutes to harmful chemical flocculants commonly used in water and wastewater treatment.</p></abstract>

Flocculants are chemicals that mediate flocculation process, by aggregating colloids from suspension to form floc. Chemical flocculants are hazardous to the environment, which inform the search for safer and eco-friendly alternatives from microorganisms. Bacterial strains were isolated from water and sediment samples collected from Sodwana Bay, South Africa, and physiological properties of the bacterial strains were observed. Flocculation test using kaolin clay suspension was done on all isolates and the ones that showed flocculating activity were identified molecularly using 16 rRNA gene sequence analysis. Forty marine bacteria isolates were gotten from sediments and water samples collected from Sodwana Bay. Most of the isolates exhibited a range of colony pigmentation (pink, creamy, yellow, and white). After purification of individual isolates, they were screened for their potential to produce bioflocculant. The result revealed that isolates marked SOD3, SOD10, SOD12, SOD26, SOD27, SOD28, SOD32, SOD33 and SOD34 produced bioflocculants as shown by the flocculating activities from their crude extract. All these isolates showed good flocculation of kaolin clay suspension above 60% (flocculating activity) except SOD12. These bioflocculant producing isolates were identified as Pseudoalteromonas sp, Alcaligenes faecalis, Bacillus subtilis, Bacillus cereus, Bacillus stratosphericus. The results showed Sodwana Bay, South Africa as a reservoir of bacteria with potential to produce flocculants. However, further studies on the optimisation of culture conditions for bioflocculant production, extraction, characterisation and application of isolates is on the way to underscore the biotechnological importance of these microbes as producers of substitutes to harmful chemical flocculants commonly used in water and wastewater treatment.

Screening for Bioflocculant-Producing Bacteria from the Marine Environment of Sodwana Bay, South Africa

Department of Biochemistry and Microbiology

Annals of Science and Technology

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Flocculants are chemicals that mediate flocculation process, by aggregating colloids from suspension to form floc. Chemical flocculants are hazardous to the...

Screening for Bioflocculant-Producing Bacteria from the Marine Environment of Sodwana Bay, South Africa

Publié en ligne: 29 août 2018

Pages: 16 - 20

Reçu: 03 oct. 2017

Accepté: 09 mars 2018

DOI: https://doi.org/10.2478/ast-2018-0010

Mots clés
Marine, Bacteria, Bioflocculant, Sediment, Sodwana Bay

© 2018 Anthony M. Ugbenyen et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Screening for Bioflocculant-Producing Bacteria from the Marine Environment of Sodwana Bay, South Africa

Publié en ligne: 29 août 2018

Pages: 16 - 20

Reçu: 03 oct. 2017

Accepté: 09 mars 2018

DOI: https://doi.org/10.2478/ast-2018-0010

Mots clésMarine, Bacteria, Bioflocculant, Sediment, Sodwana Bay

© 2018 Anthony M. Ugbenyen et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Mots clés
Marine, Bacteria, Bioflocculant, Sediment, Sodwana Bay